Grand King is a cyborg kaiju created by Juda and an antagonist in the 1984 movie, Ultraman Movie. It has also appeared in several Ultraman installments since then.
History
Ultraman Story
Grand King was created when Juda combined together the spirits of Alien Baltan, Red King, Gomora, Alien Mefilas, Eleking and Alien Hipporito. Juda then had Grand King fight the Ultras. Despite their best efforts, Ultraman, Ultraseven, Ultraman Jack, Ultraman Ace and Zoffy were unable to do any damage to the cyborg kaiju. Eventually though, Ultraman Taro returned from fighting Enmargo on Earth to assist the Ultra Brothers.
Even with Taro's help the Ultra Brothers were still unable to overcome Grand King. The Father of Ultra then suggested to the Brothers that they fuse with Taro. With the power of his brothers, Taro was able to fight evenly with Grand King, eventually finishing it off with a Cosmo Miracle Beam. With the defeat of his trump card, Juda retreated.
Ultraman Ginga
Grand King returns as Super Grand King when Alien Nackle Gray possessed Misuzu. Hikaru/Ginga and Tomoya/Jean-nine eventually discover this, and Hikaru enters Misuzu's mind an attempt to reason with her. Meanwhile, Hikaru's friends and Misuzu's father transformed into Ultraman, Ultraseven and Ultraman Tiga to try and hold off the kaiju.
Hikaru eventually convinces Misuzu to free herself, leaving Gray as the sole entity inside the monster. Misuzu then entered Ultraman Ginga with Hikaru and defeated Grand King together with Ginga Sunshine, gaining both Grand King's and Alien Nackle's Spark Dolls.
Ultra Fight Victory
Grand King was recreated by Juda Spectre as Super Grand King Spectre to destroy the Ultra Brothers. Ace attempted to defeat it with a Vertical Ultra Guillotine but Grand King destroyed it with his Bat Calibur. Ginga Victory fired a Mebium Shoot at Super Grand King, but the robot kaiju cancelled it out with his Chest Laser, which also hit and separated Ginga Victory back to Ultraman Ginga and Ultraman Victory. Victory then went to go battle Juda Spectre, leaving Ginga and the other Ultras to fight Super Grand King Spectre.
Victory later used his powers to distort Juda Spectre's distortions, immobilizing Super Grand King Spectre and allowing Ultraman Ace, Leo and Astra and Ginga to destroy it with the Metallium Ray, Ultra Double Flasher and Ginga Cross Shoot.
Ultraman Orb
Grand King appears again as Maga-Grand King. Maga-Grand King was sealed by Ultraman Taro in the distant past. Despite this, Maga-Grand King was still able to influence the opening of sinkholes in a city. Maga-Grand King was later released by Jugglus Juggler with the Fusion Card and Kaiju Cards. Gai then transformed into Ultraman Orb to combat the monster. Orb attempted several physical attacks against Maga-Grand King, none of which managed to deal any damage to it.
However, after noticing that glass reflected one of its beams, Orb tricked Maga-Grand King into firing a laser at him, reflecting the beam back at it and penetrating a hole that exposed its insides. Orb then fired a Sparion Ray into the hole, destroying Maga-Grand King. However, Jugglus managed to obtain Maga-Grand King's Kaiju Card with his Dark Ring.